Thursday, December 31, 2020

Shrinking Lakes Worldwide Blamed on Climate Crisis

The Caspian Sea, seen here from the in­ter­na­tional space sta­tion ISS, is the largest lake in the world. Its wa­ter levels are fall­ing due to cli­mate change. 
Credit: NASA/​Scott Kelly

Cli­mate change is im­pact­ing not only the oceans, but also large in­land lakes. As the world’s largest lake, the Caspian Sea is a per­fect ex­ample of how a body of wa­ter can and will change. In an art­icle in the Nature journal Communications Earth & Environment, Dr. Mat­thias Prange of MARUM – Cen­ter for Mar­ine En­vir­on­mental Sci­ences at the Uni­versity of Bre­men, and his col­leagues dis­cuss the pos­sible eco­lo­gical, polit­ical and eco­nomic con­sequences, as well as vi­able solu­tions.

While global sea levels are rising due to the cli­mate crisis and threat­en­ing near-coastal in­fra­struc­tures, higher tem­per­at­ures in other areas are hav­ing ex­actly the op­pos­ite ef­fect. The wa­ter levels are fall­ing and also caus­ing massive prob­lems. Al­though the con­sequences are equally ser­i­ous, however, de­clin­ing wa­ter levels are re­ceiv­ing less at­ten­tion ac­cord­ing to Mat­thias Prange, Thomas Wilke of the Jus­tus Liebig Uni­versity in Gießen, and Frank P. Wessel­ingh of the Uni­versity of Utrecht and the Nat­uralis Biod­iversity Cen­ter Leiden (The Neth­er­lands).

“The Caspian Sea can be viewed as rep­res­ent­at­ive of many other lakes in the world. Many people are not even aware that an in­land lake is dra­mat­ic­ally shrink­ing due to cli­mate change, as our mod­els in­dic­ate,” says Mat­thias Prange. The re­port of the In­ter­gov­ern­mental Panel on Cli­mate Change (IPCC) also failed to men­tion lakes, and dis­reg­arded the so­cial, polit­ical and eco­nomic con­sequences of global warm­ing on the af­fected re­gions. “This has to change. We need more stud­ies and a bet­ter un­der­stand­ing of the con­sequences of global warm­ing in this re­gion.” The goal must be to raise aware­ness of the con­sequences of cli­mate change for in­land seas and lakes so that ap­pro­pri­ate strategies can be de­veloped, in­clud­ing ap­proaches for other large lakes and re­gions fa­cing sim­ilar chal­lenges.

Be­cause of its size (it is the largest lake in the world) and be­cause of its re­l­at­ively high sa­lin­ity of about one per cent, which is about one-third of the salt con­cen­tra­tion in the oceans, the Caspian has been named a ‘Sea’. Its largest in­flow is the Volga River and it has no nat­ural con­nec­tion to the ocean. The wa­ter level is de­term­ined by the pro­por­tional in­flu­ences of in­flow, pre­cip­it­a­tion and evap­or­a­tion. Global warm­ing is caus­ing in­creased evap­or­a­tion, which res­ults in a de­clin­ing wa­ter level.

The Caspian Sea is an im­port­ant re­gional wa­ter reser­voir and, des­pite its salt con­tent, a bio­lo­gical and com­mer­cial cen­ter. It is bounded by Kaza­kh­stan, Turk­menistan, Iran, Azerbaijan and Rus­sia. De­pend­ing on the de­gree of global warm­ing in the fu­ture, the wa­ter level could fall by 9 to 18 meters dur­ing this cen­tury. “This would af­fect not only the biod­iversity, vari­ous spe­cies, and hab­it­ats that would dis­ap­pear. The eco­nom­ies of all the bor­der­ing coun­tries would be im­pacted, in­clud­ing har­bors, fish­er­ies and fish farm­ing.” For this reason, the au­thors ar­gue that in the fu­ture the Caspian Sea should be used as an ex­ample in sci­entific re­search to as­sess the vul­ner­ab­il­ity of cer­tain re­gions to fall­ing wa­ter levels. Be­cause no na­tion can solve the res­ult­ing con­flicts alone, they pro­pose a global task force to de­velop and co­ordin­ate strategies. The art­icle sug­gests that "in­ter­na­tional cli­mate funds" could of­fer a pos­sib­il­ity for fin­an­cing pro­jects and ad­apt­a­tion meas­ures if changes in the lake level are at­trib­uted to cli­mate change.

 





Contacts and sources: 
Dr. Mat­thias Prange
Geo­sys­tem Mod­el­ling
MARUM - Center for Marine Environmental Sciences, University of Bremen


Publication: The other side of sea level change.
Matthias Prange, Thomas Wilke, Frank P. Wesselingh. Communications Earth & Environment, 2020; 1 (1) DOI: 10.1038/s43247-020-00075-6





Origin of Life: on Earth: Discovery Supports Theory Life Arose from RNA-DNA Mix

A newly described chemical reaction could have assembled DNA building blocks before life forms and their enzymes existed.

Chemists at Scripps Research have made a discovery that supports a surprising new view of how life originated on our planet.

In a study published in the chemistry journal Angewandte Chemie, they demonstrated that a simple compound called diamidophosphate (DAP), which was plausibly present on Earth before life arose, could have chemically knitted together tiny DNA building blocks called deoxynucleosides into strands of primordial DNA.



Credit: Scripps Research 


The finding is the latest in a series of discoveries, over the past several years, pointing to the possibility that DNA and its close chemical cousin RNA arose together as products of similar chemical reactions, and that the first self-replicating molecules—the first life forms on Earth—were mixes of the two.

The discovery may also lead to new practical applications in chemistry and biology, but its main significance is that it addresses the age-old question of how life on Earth first arose. In particular, it paves the way for more extensive studies of how self-replicating DNA-RNA mixes could have evolved and spread on the primordial Earth and ultimately seeded the more mature biology of modern organisms.

“This finding is an important step toward the development of a detailed chemical model of how the first life forms originated on Earth,” says study senior author Ramanarayanan Krishnamurthy, PhD, associate professor of chemistry at Scripps Research.

The finding also nudges the field of origin-of-life chemistry away from the hypothesis that has dominated it in recent decades: The “RNA World” hypothesis posits that the first replicators were RNA-based, and that DNA arose only later as a product of RNA life forms.

Is RNA too sticky?

Krishnamurthy and others have doubted the RNA World hypothesis in part because RNA molecules may simply have been too “sticky” to serve as the first self-replicators.

A strand of RNA can attract other individual RNA building blocks, which stick to it to form a sort of mirror-image strand—each building block in the new strand binding to its complementary building block on the original, “template” strand. If the new strand can detach from the template strand, and, by the same process, start templating other new strands, then it has achieved the feat of self-replication that underlies life.

But while RNA strands may be good at templating complementary strands, they are not so good at separating from these strands. Modern organisms make enzymes that can force twinned strands of RNA—or DNA—to go their separate ways, thus enabling replication, but it is unclear how this could have been done in a world where enzymes didn’t yet exist.

A chimeric workaround

Krishnamurthy and colleagues have shown in recent studies that “chimeric” molecular strands that are part DNA and part RNA may have been able to get around this problem, because they can template complementary strands in a less-sticky way that permits them to separate relatively easily.

The chemists also have shown in widely cited papers in the past few years that the simple ribonucleoside and deoxynucleoside building blocks, of RNA and DNA respectively, could have arisen under very similar chemical conditions on the early Earth.

Moreover, in 2017 they reported that the organic compound DAP could have played the crucial role of modifying ribonucleosides and stringing them together into the first RNA strands. The new study shows that DAP under similar conditions could have done the same for DNA.

“We found, to our surprise, that using DAP to react with deoxynucleosides works better when the deoxynucleosides are not all the same but are instead mixes of different DNA 'letters' such as A and T, or G and C, like real DNA,” says first author Eddy Jiménez, PhD, a postdoctoral research associate in the Krishnamurthy lab.

“Now that we understand better how a primordial chemistry could have made the first RNAs and DNAs, we can start using it on mixes of ribonucleoside and deoxynucleoside building blocks to see what chimeric molecules are formed—and whether they can self-replicate and evolve,” Krishnamurthy says.

He notes that the work may also have broad practical applications. The artificial synthesis of DNA and RNA—for example in the “PCR” technique that underlies COVID-19 tests—amounts to a vast global business, but depends on enzymes that are relatively fragile and thus have many limitations. Robust, enzyme-free chemical methods for making DNA and RNA may end up being more attractive in many contexts, Krishnamurthy says.

Prebiotic Phosphorylation and Concomitant Oligomerization of Deoxynucleosides to form DNA” was authored by Eddy Jiménez, Clémentine Gibard and Ramanarayanan Krishnamurthy. Funding was provided by the Simons Foundation.




Contacts and sources:
Scripps Research Institute



Publication: Prebiotic Phosphorylation and Concomitant Oligomerization of Deoxynucleosides to form DNA.
Ramanarayanan Krishnamurthy, Eddy I. Jiménez, Clémentine Gibard. Angewandte Chemie International Edition, 2020; DOI: 10.1002/anie.202015910





Monday, December 28, 2020

Droughts, Viruses and Road Networks: Trends that Will Impact Our Forests


A new UCPH study assembled an array of experts to highlight major trends that will impact the world's forests, and the people living around them, in the decade ahead. These trends include drought, viral outbreaks and vast infrastructure expansions across the globe. According to the researchers, a global strategy for human-nature interaction must be developed if we intend on ensuring the survival of both.Photo: Getty Images

Earth’s forests are indispensable for both humans and wildlife: they absorb CO2, provide food for large parts of the world's population and are home to all sorts of animals. In a new agreement, the Danish government has set aside 888 million kroner to protect nature and biodiversity.

However, forest conservation measures are lagging in other countries, says Laura Vang Rasmussen, an assistant professor at the University of Copenhagen’s Department of Geosciences and Nature Management.

"It is critical for countries like Denmark, and especially countries with weaker economic conditions, to prioritize forests and have forest conservation plans. Without the adoption of conservation strategies, droughts and viral outbreaks could have severe consequences on forests and humans alike," she says.

Rasmussen, along with fellow researchers from the University of Manchester, is behind a new study in which 24 experts from the around the world have ranked the most significant trends that will affect the world's forests over the coming decade.
Drought and new viral outbreaks

In Denmark, we have seen an increase in the number of summers with scant rainfall, and in the rest of the world – particularly on the US West Coast – droughts have been responsible for massive and devastating forest fires. The new study argues that this trend will continue:

"When we lose forest, due to drought for example, the risk of spreading viruses like coronavirus increases. When forest fires disturb natural ecosystems, disease carrying animals such as bats or rats flee from their charred ecosystems into towns and villages. And, as we have seen with the coronavirus pandemic, viral outbreaks have enormous consequences on global health and economy," explains Rasmussen.
Humans are migrating from the countryside to cities, with more people on the way

More people wanting to move from rural areas into the cities can have both positive and negative consequences for the world's forests.

"It could be that the amount of forest increases as more and more farmers abandon their livelihoods in favor of higher wage urban jobs. This would allow forests room to grow. Conversely, we run the risk that ballooning urban populations will increase demand for marketable crops, which will result in more forests being cleared for agriculture," says Laura Vang Rasmussen.

Furthermore, the planet’s human population is projected to increase to roughly 8.5 billion by 2030. This will result in an increased demand for meat, cereals, vegetables, etc., meaning that more forests will need to be cleared to accommodate for fields and meat production farms and facilities.
25 million kilometres of new road networks worldwide

By 2050, global road networks are projected to expand by roughly 25 million kilometres. This is likely to have a positive effect on human mobility, allowing people to shuttle between cities with ease and more readily move and sell goods. However, the downside of road building is the inevitably of having to clear forestland for roadbed.

Besides having to look after forests for the sake of the environment and wildlife, forest conservation also relates to poverty, concludes Laura Vang Rasmussen:

"It is problematic that forest conservation, agriculture and poverty are seen as distinct from one another. Indeed, the three factors influence each other, as strategies to increase agricultural production can negatively impact forests. On the other hand, an increase in forested areas makes it more difficult for agriculture to produce enough food. As such, we hope that our research is able to contribute towards highlighting the complex dynamics between agricultural production, deforestation, poverty and food security.”





Contacts and sources:
University of Copenhagen

 





Important Milestone in the Creation of a Quantum Computer


One of the obstacles for progress in the quest for a working quantum computer has been that the working devices that go into a quantum computer and perform the actual calculations, the qubits, have hitherto been made by universities and in small numbers. But in recent years, a pan-European collaboration, in partnership with French microelectronics leader CEA-Leti, has been exploring everyday transistors--that are present in billions in all our mobile phones—for their use as qubits.

Scanning electron image of one of the Foundry-fabricated quantum dot devices. Four quantum dots can be formed in the silicon (dark grey), using four independent control wires (light grey). These wires are the control knobs that enable the so called quantum gates. (b) Schematic of the two-dimensional array device. Each Qubit (red circle) can interact with its nearest neighbor in the two-dimensional network, and circumvent a Qubit that fails for one reason or other. This setup is what “second dimension” means.

(a) 

Credit: University of Copenhagen

The French company Leti makes giant wafers full of devices, and, after measuring, researchers at the Niels Bohr Institute, University of Copenhagen, have found these industrially produced devices to be suitable as a qubit platform capable of moving to the second dimension, a significant step for a working quantum computer. The result is now published in Nature Communications.
Quantum dots in two dimensional array is a leap ahead

One of the key features of the devices is the two-dimensional array of quantum dot. Or more precisely, a two by two lattice of quantum dots. “What we have shown is that we can realize single electron control in every single one of these quantum dots. This is very important for the development of a qubit, because one of the possible ways of making qubits is to use the spin of a single electron. So reaching this goal of controlling the single electrons and doing it in a 2D array of quantum dots was very important for us”, says Fabio Ansaloni, former PhD student, now postdoc at center for Quantum Devices, NBI.

Using electron spins has proven to be advantageous for the implementation of qubits. In fact, their “quiet” nature makes spins weakly interacting with the noisy environment, an important requirement to obtain highly performing qubits.

Extending quantum computers processors to the second dimension has been proven to be essential for a more efficient implementation of quantum error correction routines. Quantum error correction will enable future quantum computers to be fault tolerant against individual qubit failures during the computations.

The importance of industry scale production


Assistant Professor at Center for Quantum Devices, NBI, Anasua Chatterjee adds: “The original idea was to make an array of spin qubits, get down to single electrons and become able to control them and move them around. In that sense it is really great that Leti was able to deliver the samples we have used, which in turn made it possible for us to attain this result. A lot of credit goes to the pan-European project consortium, and generous funding from the EU, helping us to slowly move from the level of a single quantum dot with a single electron to having two electrons, and now moving on to the two dimensional arrays. Two dimensional arrays is a really big goal, because that’s beginning to look like something you absolutely need to build a quantum computer. So Leti has been involved with a series of projects over the years, which have all contributed to this result.”
The credit for getting this far belongs to many projects across Europe


The development has been gradual. In 2015, researchers in Grenoble succeeded in making the first spin qubit, but this was based on holes, not electrons. Back then, the performance of the devices made in the “hole regime” were not optimal, and the technology has advanced so that the devices now at NBI can have two dimensional arrays in the single electron regime.

 The progress is threefold, the researchers explain: “First, producing the devices in an industrial foundry is a necessity. The scalability of a modern, industrial process is essential as we start to make bigger arrays, for example for small quantum simulators. Second, when making a quantum computer, you need an array in two dimensions, and you need a way of connecting the external world to each qubit. If you have 4-5 connections for each qubit, you quickly end up with a unrealistic number of wires going out of the low-temperature setup. But what we have managed to show is that we can have one gate per electron, and you can read and control with the same gate. And lastly, using these tools we were able to move and swap single electrons in a controlled way around the array, a challenge in itself.”
Two dimensional arrays can control errors

Controlling errors occurring in the devices is a chapter in itself. The computers we use today produce plenty of errors, but they are corrected through what is called the repetition code. In a conventional computer, you can have information in either a 0 or a 1. In order to be sure that the outcome of a calculation is correct, the computer repeats the calculation and if one transistor makes an error, it is corrected through simple majority. If the majority of the calculations performed in other transistors point to 1 and not 0, then 1 is chosen as the result. This is not possible in a quantum computer since you cannot make an exact copy of a qubit, so quantum error correction works in another way: State-of-the-art physical qubits do not have low error rate yet, but if enough of them are combined in the 2D array, they can keep each other in check, so to speak. This is another advantage of the now realized 2D array.
The next step from this milestone

The result realized at the Niels Bohr Institute shows that it is now possible to control single electrons, and perform the experiment in the absence of a magnetic field. So the next step will be to look for spins – spin signatures – in the presence of a magnetic field. This will be essential to implement single and two qubit gates between the single qubits in the array. Theory has shown that a handful of single and two qubit gates, called a complete set of quantum gates, are enough to enable universal quantum computation.

Link to the Scientific article: https://www.nature.com/articles/s41467-020-20280-3



 

Contacts and sources:
Fabio Ansaloni
Niels Bohr Institute
University of Copenhagen



 




One Psychedelic Experience May Lessen Trauma of Racial Injustice



A single positive experience on a psychedelic drug may help reduce stress, depression and anxiety symptoms in Black, Indigenous and people of color whose encounters with racism have had lasting harm, a new study suggests.

The participants in the retrospective study reported that their trauma-related symptoms linked to racist acts were lowered in the 30 days after an experience with either psilocybin (Magic Mushrooms), LSD or MDMA (Ecstasy).

 A photo collage by Imants Daksis


Credit: Imants Daksis / Wikimedia Commons

"Their experience with psychedelic drugs was so powerful that they could recall and report on changes in symptoms from racial trauma that they had experienced in their lives, and they remembered it having a significant reduction in their mental health problems afterward," said Alan Davis, co-lead author of the study and an assistant professor of social work at The Ohio State University.

Overall, the study also showed that the more intensely spiritual and insightful the psychedelic experience was, the more significant the recalled decreases in trauma-related symptoms were.

A growing body of research has suggested psychedelics have a place in therapy, especially when administered in a controlled setting. What previous mental health research has generally lacked, Davis noted, is a focus on people of color and on treatment that could specifically address the trauma of chronic exposure to racism.

Davis partnered with co-lead author Monnica Williams, Canada Research Chair in Mental Health Disparities at the University of Ottawa, to conduct the research.

"Currently, there are no empirically supported treatments specifically for racial trauma. This study shows that psychedelics can be an important avenue for healing," Williams said.

The study is published online in the journal Drugs: Education, Prevention and Policy.

The researchers recruited participants in the United States and Canada using Qualtrics survey research panels, assembling a sample of 313 people who reported they had taken a dose of a psychedelic drug in the past that they believed contributed to "relief from the challenging effects of racial discrimination." The sample comprised adults who identified as Black, Asian, Hispanic, Native American/Indigenous Canadian, Native Hawaiian and Pacific Islander.

Once enrolled, participants completed questionnaires collecting information on their past experiences with racial trauma, psychedelic use and mental health symptoms, and were asked to recall a memorable psychedelic experience and its short-term and enduring effects. Those experiences had occurred as recently as a few months before the study and as long ago as at least 10 years earlier.

The discrimination they had encountered included unfair treatment by neighbors, teachers and bosses, false accusations of unethical behavior and physical violence. The most commonly reported issues involved feelings of severe anger about being subjected to a racist act and wanting to "tell someone off" for racist behavior, but saying nothing instead.

Researchers asked participants to recall the severity of symptoms of anxiety, depression and stress linked to exposure to racial injustice in the 30 days before and 30 days after the experience with psychedelic drugs. Considering the probability that being subjected to racism is a lifelong problem rather than a single event, the researchers also assessed symptoms characteristic of people suffering from discrimination-related post-traumatic stress disorder (PTSD).

"Not everybody experiences every form of racial trauma, but certainly people of color are experiencing a lot of these different types of discrimination on a regular basis," said Davis, who also is an adjunct faculty member in the Johns Hopkins University Center for Psychedelic and Consciousness Research. "So in addition to depression and anxiety, we were asking whether participants had symptoms of race-based PTSD."

Participants were also asked to report on the intensity of three common kinds of experiences people have while under the influence of psychedelic drugs: a mystical, insightful or challenging experience. A mystical experience can feel like a spiritual connection to the divine, an insightful experience increases people's awareness and understanding about themselvess, and a challenging experience relates to emotional and physical reactions such as anxiety or difficulty breathing.

All participants recalled their anxiety, depression and stress symptoms after the memorable psychedelic experience were lower than they had been before the drug use. The magnitude of the positive effects of the psychedelics influenced their reduction in symptoms.

"What this analysis showed is that a more intense mystical experience and insightful experience, and a less intense challenging experience, is what was related to mental health benefits," Davis said.

The researchers noted in the paper that the study had limitations because the findings were based on participant recall and the entire sample of recruited research volunteers had reported benefits they associated with their psychedelic experience - meaning it cannot be assumed that psychedelics will help all people of color with racial trauma. Davis and Williams are working on proposals for clinical trials to further investigate the effects of psychedelics on mental health symptoms in specific populations, including Black, Indigenous and people of color.

"This was really the first step in exploring whether people of color are experiencing benefits of psychedelics and, in particular, looking at a relevant feature of their mental health, which is their experience of racial trauma," Davis said. "This study helps to start that conversation with this emerging treatment paradigm."
 

This work was funded by the University of Ottawa, the Canada Research Chairs Program and the National Institutes of Health. Additional co-authors included Yitong Xin of Ohio State's College of Social Work; Nathan Sepeda of Johns Hopkins; Pamela Grigas and Sinead Sinnott of the University of Connecticut; and Angela Haeny of Yale School of Medicine.

 


Contacts and sources: 
Alan Davis,
Written by Emily Caldwell
Ohio State University


Publication:





Big Bumblebees Learn Locations of Best Flowers



Big bumblebees take time to learn the locations of the best flowers, new research shows.

Meanwhile smaller bumblebees - which have a shorter flight range and less carrying capacity - don't pay special attention to flowers with the richest nectar.

University of Exeter scientists examined the "learning flights" which most bees perform after leaving flowers.

A bumblebee on a flower. 


Credit: Natalie Hempel de Ibarra


Honeybees are known to perform such flights - and the study shows bumblebees do the same, repeatedly looking back to memorise a flower's location.

"It might not be widely known that pollinating insects learn and develop individual flower preferences, but in fact bumblebees are selective," said Natalie Hempel de Ibarra, Associate Professor at Exeter's Centre for Research in Animal Behaviour.

"On leaving a flower, they can actively decide how much effort to put into remembering its location.

"The surprising finding of our study is that a bee's size determines this decision making and the learning behaviour."

In the study, captive bees visited artificial flowers containing sucrose (sugar) solution of varying concentrations.

The larger the bee, the more its learning behaviour varied depending on the richness of the sucrose solution.

Smaller bees invested the same amount of effort in learning the locations of the artificial flowers, regardless of whether sucrose concentration was high or low.

"The differences we found reflect the different roles of bees in their colonies," said Professor Hempel de Ibarra.

Credit: Natalie Hempel de Ibarra


"Large bumblebees can carry larger loads and explore further from the nest than smaller ones.

"Small ones with a smaller flight range and carrying capacity cannot afford to be as selective, so they accept a wider range of flowers.

"These small bees tend to be involved more with tasks inside the nest - only going out to forage if food supplies in the colony are running low."

The study was conducted in collaboration with scientists from the University of Sussex.

The bees were observed in greenhouses at the University of Exeter's award-winning Streatham Campus, and Professor Hempel de Ibarra thanked the university's Grounds and Gardens team for their continued support.

The study was funded by the Leverhulme Trust.

The paper, published in the journal Current Biology, is entitled: "Small and large bumblebees invest differently when learning about flowers."





Contacts and sources:
Alex Morrison
University of Exeter 






Black Holes May Be Baby Universes That Branched Off Our Universe at the Big Bang



The Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) is home to many interdisciplinary projects which benefit from the synergy of a wide range of expertise available at the institute. One such project is the study of black holes that could have formed in the early universe, before stars and galaxies were born.

Baby universes branching off of our universe shortly after the Big Bang appear to us as black holes.


Credit: Copyright: Kavli IPMU

Such primordial black holes (PBHs) could account for all or part of dark matter, be responsible for some of the observed gravitational waves signals, and seed supermassive black holes found in the center of our Galaxy and other galaxies. They could also play a role in the synthesis of heavy elements when they collide with neutron stars and destroy them, releasing neutron-rich material. In particular, there is an exciting possibility that the mysterious dark matter, which accounts for most of the matter in the universe, is composed of primordial black holes. The 2020 Nobel Prize in physics was awarded to a theorist, Roger Penrose, and two astronomers, Reinhard Genzel and Andrea Ghez, for their discoveries that confirmed the existence of black holes. Since black holes are known to exist in nature, they make a very appealing candidate for dark matter.

The recent progress in fundamental theory, astrophysics, and astronomical observations in search of PBHs has been made by an international team of particle physicists, cosmologists and astronomers, including Kavli IPMU members Alexander Kusenko, Misao Sasaki, Sunao Sugiyama, Masahiro Takada and Volodymyr Takhistov.

To learn more about primordial black holes, the research team looked at the early universe for clues. The early universe was so dense that any positive density fluctuation of more than 50 percent would create a black hole. However, cosmological perturbations that seeded galaxies are known to be much smaller. Nevertheless, a number of processes in the early universe could have created the right conditions for the black holes to form.

One exciting possibility is that primordial black holes could form from the "baby universes" created during inflation, a period of rapid expansion that is believed to be responsible for seeding the structures we observe today, such as galaxies and clusters of galaxies. During inflation, baby universes can branch off of our universe. A small baby (or "daughter") universe would eventually collapse, but the large amount of energy released in the small volume causes a black hole to form.

An even more peculiar fate awaits a bigger baby universe. If it is bigger than some critical size, Einstein's theory of gravity allows the baby universe to exist in a state that appears different to an observer on the inside and the outside. An internal observer sees it as an expanding universe, while an outside observer (such as us) sees it as a black hole. In either case, the big and the small baby universes are seen by us as primordial black holes, which conceal the underlying structure of multiple universes behind their "event horizons." The event horizon is a boundary below which everything, even light, is trapped and cannot escape the black hole.

A star in the Andromeda galaxy temporarily becomes brighter if a primordial black hole passes in front of the star, focusing its light in accordance with the theory of gravity. 
Credit: Kavli IPMU/HSC Collaboration


In their paper, the team described a novel scenario for PBH formation and showed that the black holes from the "multiverse" scenario can be found using the Hyper Suprime-Cam (HSC) of the 8.2m Subaru Telescope, a gigantic digital camera--the management of which Kavli IPMU has played a crucial role--near the 4,200 meter summit of Mt. Mauna Kea in Hawaii. Their work is an exciting extension of the HSC search of PBH that Masahiro Takada, a Principal Investigator at the Kavli IPMU, and his team are pursuing. The HSC team has recently reported leading constraints on the existence of PBHs in Niikura, Takada et. al. (Nature Astronomy 3, 524-534 (2019))

Why was the HSC indispensable in this research? The HSC has a unique capability to image the entire Andromeda galaxy every few minutes. If a black hole passes through the line of sight to one of the stars, the black hole's gravity bends the light rays and makes the star appear brighter than before for a short period of time. The duration of the star's brightening tells the astronomers the mass of the black hole. With HSC observations, one can simultaneously observe one hundred million stars, casting a wide net for primordial black holes that may be crossing one of the lines of sight.

The first HSC observations have already reported a very intriguing candidate event consistent with a PBH from the "multiverse," with a black hole mass comparable to the mass of the Moon. Encouraged by this first sign, and guided by the new theoretical understanding, the team is conducting a new round of observations to extend the search and to provide a definitive test of whether PBHs from the multiverse scenario can account for all dark matter.

 

Contacts and sources: 
John Amari
The Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) 


Publication: Journal: Physical Review Letters
Title: Exploring Primordial Black Holes from the Multiverse with Optical Telescopes
Authors: Alexander Kusenko (1, 2), Misao Sasaki (2, 3, 4), Sunao Sugiyama (2, 5), Masahiro Takada (2), Volodymyr Takhistov (1,2), and Edoardo Vitagliano (1)

Author affiliation:
1. Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095-1547, USA
2. Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS The University of Tokyo, Kashiwa, Chiba 277-8583, Japan
3. Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
4. Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan
5. Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

DOI: https://doi.org/10.1103/PhysRevLett.125.181304 (October 30, 2020)
Abstract of the paper: (Physical Review Letters)
Preprint: (arXiv.org page)








Volcanic Eruptions Directly Triggered Ocean Acidification during Early Cretaceous

Around 120 million years ago, the earth experienced an extreme environmental disruption that choked oxygen from its oceans.

Known as oceanic anoxic event (OAE) 1a, the oxygen-deprived water led to a minor — but significant — mass extinction that affected the entire globe. During this age in the Early Cretaceous Period, an entire family of sea-dwelling nannoplankton virtually disappeared.

By measuring calcium and strontium isotope abundances in nannoplankton fossils, Northwestern earth scientists have concluded the eruption of the Ontong Java Plateau large igneous province (LIP) directly triggered OAE1a. Roughly the size of Alaska, the Ontong Java LIP erupted for seven million years, making it one of the largest known LIP events ever. During this time, it spewed tons of carbon dioxide (CO2) into the atmosphere, pushing Earth into a greenhouse period that acidified seawater and suffocated the oceans. 

Calcium carbonate samples from a sediment core drilled from the mid-Pacific Mountains.
Credit: Northwestern University

“We go back in time to study greenhouse periods because Earth is headed toward another greenhouse period now,” said Jiuyuan Wang, a Northwestern Ph.D. student and first author of the study. “The only way to look into the future is to understand the past.”

The study was published online last week (Dec. 16) in the journal Geology. It is the first study to apply stable strontium isotope measurements to the study of ancient ocean anoxic events.

Andrew Jacobson, Bradley Sageman and Matthew Hurtgen — all professors of earth and planetary sciences at Northwestern’s Weinberg College of Arts and Sciences — coauthored the paper. Wang is co-advised by all three professors.
Clues inside cores

Nannoplankton and many other marine organisms build their shells out of calcium carbonate, which is the same mineral found in chalk, limestone and some antacid tablets. When atmospheric CO2 dissolves in seawater, it forms a weak acid that can inhibit calcium carbonate formation and may even dissolve preexisting carbonate.

Brad Sageman
Credit: Northwestern University

To study the earth’s climate during the Early Cretaceous, the Northwestern researchers examined a 1,600-meter-long sediment core taken from the mid-Pacific Mountains. The carbonates in the core formed in a shallow-water, tropical environment approximately 127 to 100 million years ago and are presently found in the deep ocean.

“When you consider the Earth’s carbon cycle, carbonate is one of the biggest reservoirs for carbon,” Sageman said. “When the ocean acidifies, it basically melts the carbonate. We can see this process impacting the biomineralization process of organisms that use carbonate to build their shells and skeletons right now, and it is a consequence of the observed increase in atmospheric CO2 due to human activities.” 

Strontium as corroborating evidence

Several previous studies have analyzed the calcium isotope composition of marine carbonate from the geologic past. The data can be interpreted in a variety of ways, however, and calcium carbonate can change throughout time, obscuring signals acquired during its formation. In this study, the Northwestern researchers also analyzed stable isotopes of strontium — a trace element found in carbonate fossils — to gain a fuller picture.
'
Andrew Jacobson

Credit: Northwestern University

“Calcium isotope data can be interpreted in a variety of ways,” Jacobson said. “Our study exploits observations that calcium and strontium isotopes behave similarly during calcium carbonate formation, but not during alteration that occurs upon burial. In this study, the calcium-strontium isotope ‘multi-proxy’ provides strong evidence that the signals are ‘primary’ and relate to the chemistry of seawater during OAE1a.”

“Stable strontium isotopes are less likely to undergo physical or chemical alteration over time,” Wang added. “Calcium isotopes, on the other hand, can be easily altered under certain conditions.”

The team analyzed calcium and strontium isotopes using high-precision techniques in Jacobson’s clean laboratory at Northwestern. The methods involve dissolving carbonate samples and separating the elements, followed by analysis with a thermal ionization mass spectrometer.

Researchers have long suspected that LIP eruptions cause ocean acidification. “There is a direct link between ocean acidification and atmospheric CO2 levels,” Jacobson said. “Our study provides key evidence linking eruption of the Ontong Java Plateau LIP to ocean acidification. This is something people expected should be the case based on clues from the fossil record, but geochemical data were lacking.”
Modeling future warming

By understanding how oceans responded to extreme warming and increased atmospheric CO2, researchers can better understand how earth is responding to current, human-caused climate change. Humans are currently pushing the earth into a new climate, which is acidifying the oceans and likely causing another mass extinction.

“The difference between past greenhouse periods and current human-caused warming is in the timescale,” Sageman said. “Past events have unfolded over tens of thousands to millions of years. We’re making the same level of warming (or more) happen in less than 200 years.”

“The best way we can understand the future is through computer modeling,” Jacobson added. “We need climate data from the past to help shape more accurate models of the future.”

The study, “Stable Ca and Sr isotopes support volcanically-triggered biocalcification crisis during Oceanic Anoxic Event 1a,” was supported by the David and Lucile Packard Foundation (award number 2007-31757) and the National Science Foundation (award number EAR-0723151). This work was jump-started with supported from the Ubben Program for Climate and Carbon Science at Northwestern University, which funded previous, related work on the topic.

 


Contacts and sources:
Amanda Morris
Northwestern University

 





Why an Early Start Is key to Developing Musical Skill Later in Life

Among the many holiday traditions scuttled by pandemic restrictions this year are live concerts featuring skilled musicians. These gifted performers can often play with such ease that it is easy to underestimate the countless hours of practice that went into honing their craft.

But could there be more to mastering music? Is there, as some have suggested, a developmental period early in life when the brain is especially receptive to musical training? The answer, according to new research published in the journal Psychological Science, is probably not. 
Credit: Association for Psychological Science

“It is a common observation that successful musicians often start their musical training early,” said Laura Wesseldijk, a researcher at the Karolinska Institute in Sweden and first author on the paper. “One much-discussed explanation is that there may be a period in early childhood during which the brain is particularly susceptible to musical stimulation. We found, however, that the explanation to why an early start matters may be more complicated and interesting than previously believed.”

While the new study supports the idea that an early start is associated with higher levels of musical skills and achievement in adulthood, the underlying reasons for this may have more to do with familial influences—such as genetic factors and an encouraging musical family environment—along with accumulating more total practice time than those who start later in life.

To untangle these effects, Wesseldijk and her colleagues recruited 310 professional musicians from various Swedish music institutions, such as orchestral and music schools. The researchers also used data from an existing research project, the Study of Twin Adults: Genes and Environment (STAGE). Participants from both studies were tested on musical aptitude and achievement. They also answered a series of questions that gauged how often they practiced and the age of onset of musical training. The STAGE data also provided genetic information on its participants.

By comparing the results from these two independent studies, the researchers were able to show that an earlier start age is associated with musical aptitude, both in amateurs and professional musicians, even after controlling for accumulated practice time. They then evaluated starting age in a manner that accounted for the genetic data from the STAGE study.

The results indicate that genetic factors—possibly related to musical interest and talent—have a substantial influence on the age individuals start music practice and their future musical aptitude. When controlling for familial factors, namely shared genetic and environmental influences, such as a home environment that is steeped in music, there was no additional association between an earlier start age and musicality.

Additional background on the psychology of music can be found in APS’s Research Topics.

A possible explanation for these results could be that children who display more talent in a particular field, such as music, are encouraged to start practicing earlier. Another possibility is that a musically active, interested, and talented family provides a musical environment for the child, while also passing on their genetic predispositions to engage in music.

“I think we have really investigated effects of the age you start musical training to the fullest,” said Wesseldijk. “Personally, as someone who practices music, it is always great to shed light on some of the factors, within the gene environmental interplay, that influence music skills.”




Contacts and sources: 
Charles Blue
Association for Psychological Science


Publication: Why Is an Early Start of Training Related to Musical Skills in Adulthood? A Genetically Informative Study.
Laura W. Wesseldijk, Miriam A. Mosing, Fredrik Ullén. Psychological Science, 2020; 095679762095901 DOI: 10.1177/0956797620959014








Early Mammal with Remarkably Precise Bite



Paleontologists at the University of Bonn have succeeded in reconstructing the chewing motion of an early mammal that lived almost 150 million years ago. This showed that its teeth worked extremely precisely and surprisingly efficiently. Yet it is possible that this very aspect turned out to be a disadvantage in the course of evolution. The study is published in the journal "Scientific Reports".

The investigated dentition of P. fruitaensis. The upper molars (M2, M3) are offset from the lower ones (m2, m3). This causes the cusps to interlock in a way that creates a sharp cutting edge. 

    Credit: © Thomas Martin, Kai R. K. Jäger / University of Bonn

At just twenty centimeters long, the least weasel is considered the world's smallest carnivore alive today. The mammal that researchers at the University of Bonn have now studied is unlikely to have been any bigger. However, the species to which it belongs has long been extinct: Priacodon fruitaensis (the scientific name) lived almost 150 million years ago, at a time when dinosaurs dominated the animal world and the triumph of mammals was still to come.

In their study, the paleontologists from the Institute for Geosciences at the University of Bonn analyzed parts of the upper and lower jaw bones of a fossil specimen. More precisely: its cheek teeth (molars). Because experts can tell a lot from these, not only about the animal’s diet, but also about its position in the family tree. In P. fruitaensis, each molar is barely larger than one millimeter. This means that most of their secrets remain hidden from the unarmed eye.

The researchers from Bonn therefore used a special tomography method to produce high-resolution three-dimensional images of the teeth. They then analyzed these micro-CT images using various tools, including special software that was co-developed at the Bonn-based institute. "Until now, it was unclear exactly how the teeth in the upper and lower jaws fit together," explains Prof. Thomas Martin, who holds the chair of paleontology at the University of Bonn. "We have now been able to answer that question."

How did creatures chew 150 million years ago?

The upper and lower jaws each contain several molars. In the predecessors of mammals, molar 1 of the upper jaw would bite down precisely on molar 1 of the lower jaw when chewing. In more developed mammals, however, the rows of teeth are shifted against each other. Molar 1 at the top therefore hits exactly between molar 1 and molar 2 when biting down, so that it comes into contact with two molars instead of one. But how were things in the early mammal P. fruitaensis?

"We compared both options on the computer," explains Kai Jäger, who wrote his doctoral thesis in Thomas Martin's research group. "This showed that the animal bit down like a modern mammal." The researchers simulated the entire chewing motion for both alternatives. In the more original version, the contact between the upper and lower jaws would have been too small for the animals to crush the food efficiently. This is different with the "more modern" alternative: In this case, the cutting edges of the molars slid past each other when chewing, like the blades of pinking shears that children use today for arts and crafts.

Its dentition therefore must have made it easy for P. fruitaensis to cut the flesh of its prey. However, the animal was probably not a pure carnivore: Its molars have cone-shaped elevations, similar to the peaks of a mountain. "Such cusps are particularly useful for perforating and crushing insect carapaces," says Jäger. "They are therefore also found in today's insectivores." However, the combination of carnivore and insectivore teeth is probably unique in this form.

The cusps are also noticeable in other ways: They are practically the same size in all molars. This made the dentition extremely precise and efficient. However, these advantages came at a price: Small changes in the structure of the cusps would probably have dramatically worsened the chewing performance. “This potentially made it more difficult for the dental apparatus to evolve," Jäger says.

This type of dentition has in fact survived almost unchanged in certain lineages of evolutionary history over a period of 80 million years. At some point, however, its owners became extinct - perhaps because their teeth could not adapt to changing food conditions.

Funding:

The study was funded by the German Research Foundation (DFG) within Research Group 771 "Function and performance enhancement in the mammalian dentition-phylogenetic and ontogenetic impact on the masticatory apparatus". It also received a grant from the National Science Foundation of the USA.

Publication: Kai R. K. Jäger, Richard L. Cifelli & Thomas Martin: Molar occlusion and jaw roll in early crown mammals; Scientific Reports, DOI: 10.1038/s41598-020-79159-4
https://www.nature.com/articles/s41598-020-79159-4
 







Contacts and sources: 
Prof. Dr. Thomas Martin
University of Bonn



Publication: Molar occlusion and jaw roll in early crown mammals
Kai R. K. Jäger, Richard L. Cifelli, Thomas Martin. . Scientific Reports, 2020; 10 (1) DOI: 10.1038/s41598-020-79159-4





Sunday, December 27, 2020

Earthquakes Causing Rapid Arctic Warming Says Geoscientist

A researcher from MIPT has proposed a new explanation for the Arctic's rapid warming. In his recent paper in Geosciences, he suggests that the warming could have been triggered by a series of great earthquakes.

Arctic air temperature anomaly variation since 1900. The thick red lines indicate two phases of abrupt warming. Data compiled by Arctic and Antarctic Research Institute.

Credit: Leopold Lobkovsky/Geosciences

Global warming is one of the pressing issues faced by civilization. It is widely believed to be caused by human activity, which increases the concentration of greenhouse gases in the atmosphere. However, this view does not explain why temperatures sometimes rise fairly abruptly.

In the Arctic, one of the factors driving climate warming is the release of methane from permafrost and metastable gas hydrates in the shelf zone. Since researchers began to monitor temperatures in the Arctic, the region has seen two periods of abrupt warming: first in the 1920s and '30s, and then beginning in 1980 and continuing to this day.

Leopold Lobkovsky, who authored the study reported in this story, is a member of the Russian Academy of Sciences and the head of the MIPT Laboratory for Geophysical Research of the Arctic and Continental Margins of the World Ocean. In his paper, the scientist hypothesized that the unexplained abrupt temperature changes could have been triggered by geodynamic factors. Specifically, he pointed to a series of great earthquakes in the Aleutian Arc, which is the closest seismically active area to the Arctic.

To test his hypothesis, Lobkovsky had to answer three questions. First, did the dates of the great earthquakes coincide with temperature jumps? Second, what is the mechanism that enables the lithospheric disturbances to propagate over more than 2,000 kilometers from the Aleutian Islands to the Arctic shelf region? Third, how do these disturbances intensify methane emissions?

The answer to the first question came from historical data analysis. It turned out that the Aleutian Arc was indeed the site of two series of great earthquakes in the 20th century (more details below the text). Each of them preceded an abrupt rise in temperature by about 15 to 20 years.

Aleutian Islands are an archipelago comprising dozens of islands with 40 active and 17 dormant volcanoes  


Credit: Shutterstock


It took a model of lithospheric excitation dynamics to answer the second question. The model used by the researcher describes the propagation of so-called tectonic waves and predicts that they should travel at about 100 kilometers per year. This agrees with the delay between each of the great earthquake series and the subsequent temperature hike, as it took the disturbances 15 to 20 years to get transmitted over 2,000 kilometers.

To answer the third question, the researcher proposed the following explanation: The deformation waves arriving in the shelf zone cause minor additional stresses in the lithosphere, which are sufficient to disrupt the internal structure of the metastable gas hydrates and permafrost storing captured methane. This releases methane into the water of the shelf and atmosphere, leading to climate warming in the region due to the greenhouse effect.

"There is a clear correlation between the great earthquakes in the Aleutian Arc and the phases of climate warming. A mechanism exists for physically transmitting the stresses in the lithosphere at the appropriate velocities. And these added stresses are capable of destroying metastable gas hydrates and permafrost, releasing methane. Each of the three components in this scheme is logical and lends itself to mathematical and physical explanation. Importantly, it explains a known fact -- the abrupt rise in temperature anomalies in the Arctic -- which remained unaccounted for by the previous models," Lobkovsky commented.

According to the researcher, his model will benefit from discussion and will likely be improved, and there is much to be done in order to confirm or rule out the proposed mechanism.
 

The research reported in this story was carried out at MIPT with the support of the Russian Science Foundation, grant No. 20-17-00140.

Two great earthquake series. The first one started with a magnitude 8 earthquake in 1899 in the eastern part of the Aleutian Arc, followed by two more great earthquakes in the western part of the islands, with magnitudes of 8.3 and 8.4. The second series began with an 8.6 magnitude earthquake in 1957, followed by the 9.3 magnitude 1964 Alaskan earthquake. The following year, an 8.7 magnitude earthquake shook the western part of the arc. Each of these devastating seismic events had underground sources spanning hundreds of kilometers.


 
Contacts and sources: 
Alena Akimova 
Moscow Institute of Physics and Technology


 







Ancient DNA Reveals 1200 Mile Open Ocean Voyage 3500 Years Ago to Pepo[;e the Marianas Islands

Researchers find that present-day Mariana Islanders’ ancestry is linked to the Philippines

Compared to the first peopling of Polynesia, the settlement of the Mariana Islands in the Western Pacific, which happened around 3,500 years ago, has received little attention. Researchers from the Max Planck Institute for Evolutionary Anthropology, the Australian National University and the University of Guam have now obtained answers to long debated questions regarding the origin of the first colonizers of the Marianas and their relationship to the people who initially settled in Polynesia.


Archaeologist Mike T. Carson during the initial uncovering of one of the skeletons.

Credit: © Hsiao-chun Hung

To reach the Mariana Islands in the Western Pacific, humans crossed more than 2,000 kilometres of open ocean, and around 2,000 years earlier than any other sea travel over an equally long distance. They settled in the Marianas around 3,500 years ago, slightly earlier than the initial settlement of Polynesia.

“We know more about the settlement of Polynesia than we do about the settlement of the Mariana Islands”, says first author Irina Pugach, a researcher at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. The researchers wanted to find out where people came from to get to the Marianas and how the ancestors of the present Mariana Islanders, the Chamorro, might be related to Polynesians.


Excavation work area outside the Ritidian Beach Cave site in northern Guam, Mariana Islands.

© Hsiao-chun Hung

To address these questions the researchers obtained ancient DNA data from two skeletons from the Ritidian Beach Cave site in northern Guam, dating to around 2,200 years ago. “We found that the ancestry of these ancient skeletons is linked to the Philippines”, says Pugach. “These findings strengthen the picture that has emerged from linguistic and archaeological studies, pointing to an Island Southeast Asia origin for the first settlers of the Marianas,” says co-author Mike T. Carson, an archaeologist at the Micronesian Area Research Center at the University of Guam.

“We also find a close link between the ancient Guam skeletons and early Lapita individuals from Vanuatu and Tonga in the Western Pacific region”, adds Pugach. “This suggests that the Marianas and Polynesia may have been colonized from the same source population, and raises the possibility that the Marianas played a role in the eventual settlement of Polynesia.”

The researchers point out that while the new results provide interesting new insights, they are based on only two skeletons that date from around 1,400 years after the first human settlement in Guam. “The peopling of Guam and the settlement of such remote archipelagos in Oceania needs further investigation”, says senior author Mark Stoneking of the Max Planck Institute for Evolutionary Anthropology.

 


Contacts and sources: 
Sandra Jacob
Max Planck Institute for Evolutionary Anthropology


Publication: Irina Pugach, Alexander Hübner, Hsiao-chun Hung, Matthias Meyer, Mike T. Carson, Mark Stoneking
Ancient DNA from Guam and the peopling of the Pacific
PNAS, 22 December 2020, https://doi.org/10.1073/pnas.2022112118









Micro-Plastic Is Blowing in the Wind, Climbing the Food Cbain


The discovery of microplastics in the air above the ocean reveals the spread of this hazardous pollution

As the plastic in our oceans breaks up into smaller and smaller bits without breaking down chemically, the resulting microplastics are becoming a serious ecological problem. A new study at the Weizmann Institute of Science reveals a troubling aspect of microplastics – defined as particles smaller than 5 mm across. They are swept up into the atmosphere and carried on the wind to far-flung parts of the ocean, including those that appear to be clear. Analysis reveals that such minuscule fragments can stay airborne for hours or days, spreading the potential to harm the marine environment and, by climbing up the food chain, to affect human health.

“A handful of studies have found microplastics in the atmosphere right above the water near shorelines,” says Dr. Miri Trainic, in the groups of Prof. Ilan Koren, of the Institute’s Earth and Planetary Sciences Department and Prof. Assaf Vardi of the Institute’s Plant and Environmental Sciences Department. “But we were surprised to find a non-trivial amount above seemingly pristine water.”

Koren, Vardi and Prof. Yinon Rudich of the Institute’s Earth and Planetary Sciences Department have been collaborating for a number of years on studies designed to understand the interface between ocean and air. While the way the oceans absorb materials from the atmosphere has been well studied, the opposite-direction’s process – aerosolization, in which volatiles, viruses, algal fragments and other particles are swept from seawater into the atmosphere – had been much less investigated.

As part of this ongoing effort, aerosol samples were collected for study in the Weizmann labs during the 2016 run of the Tara research vessel, a schooner on which several international research teams at a time come together to study the effects of climate change, primarily on marine biodiversity. The Weizmann team affixed the inlet of their measuring equipment to the top of one of the Tara’s masts (so as to avoid any aerosols produced by the schooner, itself) and Dr. J. Michel Flores, of Koren’s group, joined the mission to tend to the collecting as the schooner sailed across the North Atlantic Ocean.

The research setup included an intake at the top of the mast. The Tara research schooner, 2016. 
Credit: The Bulletin of the American Meteorological Society

Identifying and quantifying the microplastic bits trapped in their aerosol samples was far from easy, as the particles turned out to be hard to pick out under the microscope. To understand exactly what plastic was getting into the atmosphere, the team conducted Raman spectroscopy measurements, with the assistance of Dr. Iddo Pinkas of Chemical Research Support, to determine their chemical makeup and size. The researchers detected high levels of common plastics – polystyrene, polyethylene, polypropylene and more – in their samples. Then, calculating the shape and mass of the microplastic particles, along with the average wind directions and speeds over the oceans, the team showed that the source of these microplastics was most likely the plastic bags and other plastic waste that had been discarded near the shore and made its way into the ocean hundreds of kilometers away.

Checking the seawater beneath the sample sites showed the same type of plastic as in the aerosol, providing support for the idea that microplastics enter the atmosphere through bubbles on the ocean surface or are picked up by winds, and are transported on air currents to remote parts of the ocean.

“Once microplastics are in the atmosphere, they dry out, and they are exposed to UV light and atmospheric components with which they interact chemically,” says Trainic. “That means the particles that fall back into the ocean are likely to be even more harmful or toxic than before to any marine life that ingests them.”
 
“On top of that,” adds Vardi, “some of these plastics become scaffolds for bacterial growth for all kinds of marine bacteria, so airborne plastic could be offering a free ride to some species, including pathogenic bacteria that are harmful to marine life and humans.”

“The real amount of microplastic in the ocean aerosols is almost certainly greater than what our measurements showed, because our setup was unable to detect those particles below a few micrometers in size,” says Trainic. “For example, in addition to plastics that break down into even smaller pieces, there are the nanoparticles that are added to cosmetics and which are easily washed into the ocean, or are formed in the ocean through microplastic fragmentation.”

Size, in the case of plastic particles, does matter, not only because lighter ones may stay airborne for longer periods. When they do land on the water’s surface, they are more likely to be eaten by equally small marine life, which, of course, cannot digest them. Thus, every one of these particles has the potential to harm a marine organism or to work its way up the food chain and into our bodies.

“Last, but not least, like all aerosols, microplastics become part of the large planetary cycles – for example, carbon and oxygen – as they interact with other parts of the atmosphere,” says Koren. “Because they are both lightweight and long-lived, we will be seeing more microplastics transported in the air as the plastics that are already polluting our oceans break up – even if we do not add any further plastics to our waterways.” he adds.
 


Contacts and sources: 
Weizmann Institute of Science



Publication: Airborne microplastic particles detected in the remote marine atmosphere.
Miri Trainic, J. Michel Flores, Iddo Pinkas, Maria Luiza Pedrotti, Fabien Lombard, Guillaume Bourdin, Gabriel Gorsky, Emmanuel Boss, Yinon Rudich, Assaf Vardi, Ilan Koren. Communications Earth & Environment, 2020; 1 (1) DOI: 10.1038/s43247-020-00061-y





Masks Not Enough to Stop COVID-19’s Spread Without Distancing



Simply wearing a mask may not be enough to prevent the spread of COVID-19 without social distancing.

In Physics of Fluids, by AIP Publishing, researchers tested how five different types of mask materials impacted the spread of droplets that carry the coronavirus when we cough or sneeze.

Every material tested dramatically reduced the number of droplets that were spread. But at distances of less than 6 feet, enough droplets to potentially cause illness still made it through several of the materials.

The device used by researchers to study how masks block simulated respiratory droplets carrying the COVID-19 virus.
 CREDIT: Javed Akhtar

“A mask definitely helps, but if the people are very close to each other, there is still a chance of spreading or contracting the virus,” said Krishna Kota, an associate professor at New Mexico State University and one of the article’s authors. “It’s not just masks that will help. It’s both the masks and distancing.”

At the university, researchers built a machine that uses an air generator to mimic human coughs and sneezes. The generator was used to blow tiny liquid particles, like the airborne droplets of sneezes and coughs, through laser sheets in an airtight square tube with a camera.

They blocked the flow of the droplets in the tube with five different types of mask materials — a regular cloth mask, a two-layer cloth mask, a wet two-layer cloth mask, a surgical mask, and a medical-grade N-95 mask.

Each of the masks captured the vast majority of droplets, ranging from the regular cloth mask, which allowed about 3.6% of the droplets to go through, to the N-95 mask, which statistically stopped 100% of the droplets. But at distances of less than 6 feet, even those small percentages of droplets can be enough to get someone sick, especially if a person with COVID-19 sneezes or coughs multiple times.

A single sneeze can carry up to 200 million tiny virus particles, depending on how sick the carrier is. Even if a mask blocks a huge percentage of those particles, enough could escape to get someone sick if that person is close to the carrier.

“Without a face mask, it is almost certain that many foreign droplets will transfer to the susceptible person,” Kota said. “Wearing a mask will offer substantial, but not complete, protection to a susceptible person by decreasing the number of foreign airborne sneeze and cough droplets that would otherwise enter the person without the mask. Consideration must be given to minimize or avoid close face-to-face or frontal human interactions, if possible.”

The study also did not account for leakage from masks, whether worn properly or improperly, which can add to the number of droplets that make their way into the air.

From the Journal: Physics of Fluids
Link to article: Can face masks offer protection from airborne sneeze and cough droplets in close-up, face-to-face human interactions? A quantitative study
DOI: 10.1063/5.0035072




Contacts and sources: 
American Institute of Physics




Publication: Can face masks offer protection from airborne sneeze and cough droplets in close-up, face-to-face human interactions?—A quantitative study.
Javed Akhtar, Abner Luna Garcia, Leonardo Saenz, Sarada Kuravi, Fangjun Shu, Krishna Kota. Physics of Fluids, 2020; 32 (12): 127112 DOI: 10.1063/5.0035072






UV-Emitting LED Lights Found to Kill Coronavirus, Could Be Installed in Ventilation Systems

Researchers from Tel Aviv University (TAU) have proven that the coronavirus can be killed efficiently, quickly, and cheaply using ultraviolet (UV) light-emitting diodes (UV-LEDs). They believe that the UV-LED technology will soon be available for private and commercial use.



Credit: TAU

This is the first study conducted on the disinfection efficiency of UV-LED irradiation at different wavelengths or frequencies on a virus from the family of coronaviruses. The study was led by Professor Hadas Mamane, Head of the Environmental Engineering Program at TAU’s School of Mechnical Engineering, Iby and Aladar Fleischman Faculty of Engineering. The article was published in November 2020 issue of the Journal of Photochemistry and Photobiology B: Biology.

“The entire world is currently looking for effective solutions to disinfect the coronavirus,” said Professor Mamane. “The problem is that in order to disinfect a bus, train, sports hall, or plane by chemical spraying, you need physical manpower, and in order for the spraying to be effective, you have to give the chemical time to act on the surface. Disinfection systems based on LED bulbs, however, can be installed in the ventilation system and air conditioner, for example, and sterilize the air sucked in and then emitted into the room.

“We discovered that it is quite simple to kill the coronavirus using LED bulbs that radiate ultraviolet light,” she explained. “We killed the viruses using cheaper and more readily available LED bulbs, which consume little energy and do not contain mercury like regular bulbs. Our research has commercial and societal implications, given the possibility of using such LED bulbs in all areas of our lives, safely and quickly.”

The researchers tested the optimal wavelength for killing the coronavirus and found that a length of 285 nanometers (nm) was almost as efficient in disinfecting the virus as a wavelength of 265 nm, requiring less than half a minute to destroy more than 99.9% of the coronaviruses. This result is significant because the cost of 285 nm LED bulbs is much lower than that of 265 nm bulbs, and the former are also more readily available.

Eventually, as the science develops, the industry will be able to make the necessary adjustments and install the bulbs in robotic systems or air conditioning, vacuum, and water systems, and thereby be able to efficiently disinfect large surfaces and spaces. Professor Mamane believes that the technology will be available for use in the near future.

It is important to note that it is very dangerous to try to use this method to disinfect surfaces inside homes. To be fully effective, a system must be designed so that a person is not directly exposed to the light.

In the future, the researchers will test their unique combination of integrated damage mechanisms and more ideas they recently developed on combined efficient direct and indirect damage to bacteria and viruses on different surfaces, air, and water.

The study was conducted in collaboration with Professor Yoram Gerchman of Oranim College; Dr. Michal Mandelboim, Director of the National Center for Influenza and Respiratory Viruses at Sheba Medical Center at Tel HaShomer; and Nehemya Friedman from Tel Hashomer.

The research paper is available at the journal’s web site here.








Contacts and sources: 
American Friends of Tel Aviv University


Publication: UV-LED disinfection of Coronavirus: Wavelength effect. Yoram Gerchman, Hadas Mamane, Nehemya Friedman, Michal Mandelboim. Journal of Photochemistry and Photobiology B: Biology, 2020; 212: 112044 DOI: 10.1016/j.jphotobiol.2020.112044





Saturday, December 26, 2020

Promising Mini Antibodies Against COVID-19 From a Llama Isolated



Preliminary results suggest anti-COVID19 nanobodies may be effective at preventing and diagnosing infections. NIH scientists showed that anti-COVID-19 nanobodies from a llama may be an effective tool in the battle against the COVID-19 virus


Credit: Courtesy of Brody lab NIH/NINDS.

National Institutes of Health researchers have isolated a set of promising, tiny antibodies, or “nanobodies,” against SARS-CoV-2 that were produced by a llama named Cormac. Preliminary results published in Scientific Reports suggest that at least one of these nanobodies, called NIH-CoVnb-112, could prevent infections and detect virus particles by grabbing hold of SARS-CoV-2 spike proteins. In addition, the nanobody appeared to work equally well in either liquid or aerosol form, suggesting it could remain effective after inhalation. SARS-CoV-2 is the virus that causes COVID-19.

The study was led by a pair of neuroscientists, Thomas J. “T.J.” Esparza, B.S., and David L. Brody, M.D., Ph.D., who work in a brain imaging lab at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS).

“For years TJ and I had been testing out how to use nanobodies to improve brain imaging. When the pandemic broke, we thought this was a once in a lifetime, all-hands-on-deck situation and joined the fight,” said Dr. Brody, who is also a professor at Uniformed Services University for the Health Sciences and the senior author of the study. “We hope that these anti-COVID-19 nanobodies may be highly effective and versatile in combating the coronavirus pandemic.”

NIH scientists showed that nanobodies isolated from a llama may prevent COVID-19 infections. Infections happen when SARS-CoV-2 virus spike proteins (yellow) latch onto ACE2 receptors (blue) that line the outside of a cell. The NIH nanobodies (grey) may prevent infections by covering spike proteins, which blocks binding to the ACE2 receptor. 


Courtesy of Brody lab, NIH/NINDS

A nanobody is a special type of antibody naturally produced by the immune systems of camelids, a group of animals that includes camels, llamas, and alpacas. On average, these proteins are about a tenth the weight of most human antibodies. This is because nanobodies isolated in the lab are essentially free-floating versions of the tips of the arms of heavy chain proteins, which form the backbone of a typical Y-shaped human IgG antibody. These tips play a critical role in the immune system’s defenses by recognizing proteins on viruses, bacteria, and other invaders, also known as antigens.

Because nanobodies are more stable, less expensive to produce, and easier to engineer than typical antibodies, a growing body of researchers, including Mr. Esparza and Dr. Brody, have been using them for medical research. For instance, a few years ago scientists showed that humanized nanobodies may be more effective at treating an autoimmune form of thrombotic thrombocytopenic purpura, a rare blood disorder, than current therapies.

Since the pandemic broke, several researchers have produced llama nanobodies against the SARS-CoV-2 spike protein that may be effective at preventing infections. In the current study, the researchers used a slightly different strategy than others to find nanobodies that may work especially well.

“The SARS-CoV-2 spike protein acts like a key. It does this by opening the door to infections when it binds to a protein called the angiotensin converting enzyme 2 (ACE2) receptor, found on the surface of some cells,” said Mr. Esparza, who is also an employee of the Henry M. Jackson Foundation for the Advancement of Military Medicine and the lead author of the study. “We developed a method that would isolate nanobodies that block infections by covering the teeth of the spike protein that bind to and unlock the ACE2 receptor.”

To do this, the researchers immunized Cormac five times over 28 days with a purified version of the SARS-CoV-2 spike protein. After testing hundreds of nanobodies they found that Cormac produced 13 nanobodies that might be strong candidates.


NIH scientists isolated tiny antibodies, or nanobodies, against COVID-19 from a llama named Cormac
Courtesy of Triple J Farms, Bellingham, WA.

Initial experiments suggested that one candidate, called NIH-CoVnb-112, could work very well. Test tube studies showed that this nanobody bound to the ACE2 receptor 2 to 10 times stronger than nanobodies produced by other labs. Other experiments suggested that the NIH nanobody stuck directly to the ACE2 receptor binding portion of the spike protein.

Then the team showed that the NIH-CoVnB-112 nanobody could be effective at preventing coronavirus infections. To mimic the SARS-CoV-2 virus, the researchers genetically mutated a harmless “pseudovirus” so that it could use the spike protein to infect cells that have human ACE2 receptors. The researchers saw that relatively low levels of the NIH-CoVnb-112 nanobodies prevented the pseudovirus from infecting these cells in petri dishes.

Importantly, the researchers showed that the nanobody was equally effective in preventing the infections in petri dishes when it was sprayed through the kind of nebulizer, or inhaler, often used to help treat patients with asthma.

“One of the exciting things about nanobodies is that, unlike most regular antibodies, they can be aerosolized and inhaled to coat the lungs and airways,” said Dr. Brody.

The team has applied for a patent on the NIH-CoVnB-112 nanobody.

“Although we have a lot more work ahead of us, these results represent a promising first step,” said Mr. Esparza. “With support from the NIH we are quickly moving forward to test whether these nanobodies could be safe and effective preventative treatments for COVID-19. Collaborators are also working to find out whether they could be used for inexpensive and accurate testing.”


Contacts and sources:
NIH/National Institute of Neurological Disorders and Stroke


Publication: High affinity nanobodies block SARS-CoV-2 spike receptor binding domain interaction with human angiotensin converting enzyme. S Thomas J. Esparza, Negin P. Martin, George P. Anderson, Ellen R. Goldman, David L. Brody.cientific Reports, 2020; 10 (1) DOI: 10.1038/s41598-020-79036-0






Increased Meat Consumption Associated With Symptoms Of Childhood Asthma

 Substances present in cooked meats are associated with increased wheezing in children, Mount Sinai researchers report. Their study, published in Thorax, highlights pro-inflammatory compounds called advanced glycation end-products (AGEs) as an example of early dietary risk factors that may have broad clinical and public health implications for the prevention of inflammatory airway disease.

Meat for sale in a supermarket



Asthma prevalence among children in the United States has risen over the last few decades. Researchers found that dietary habits established earlier in life may be associated with wheezing and potentially the future development of asthma.

Researchers examined 4,388 children between 2 and 17 years old from the 2003-2006 National Health and Nutrition Examination Survey (NHANES), a program of the National Center for Health Statistics, which is part of the U.S. Centers for Disease Control and Prevention. It is designed to evaluate the health and nutritional status of adults and children in the United States through interviews and physical examinations.

The researchers used NHANES survey data to evaluate associations between dietary AGE and meat consumption frequencies, and respiratory symptoms. They found that higher AGE intake was significantly associated with increased odds of wheezing, importantly including wheezing that disrupted sleep and exercise, and that required prescription medication. Similarly, higher intake of non-seafood meats was associated with wheeze-disrupted sleep and wheezing that required prescription medication.

“We found that higher consumption of dietary AGEs, which are largely derived from intake of non-seafood meats, was associated with increased risk of wheezing in children, regardless of overall diet quality or an established diagnosis of asthma,” said Jing Gennie Wang, MD, lead author of the study, and a former fellow in Pulmonary, Critical Care and Sleep Medicine at the Icahn School of Medicine at Mount Sinai.

"Research identifying dietary factors that influence respiratory symptoms in children is important, as these risks are potentially modifiable and can help guide health recommendations. Our findings will hopefully inform future longitudinal studies to further investigate whether these specific dietary components play a role in childhood airways disease such as asthma," said Sonali Bose, MD, senior author, and Assistant Professor of Pulmonary, Critical Care and Sleep Medicine and Pediatrics at Icahn School of Medicine at Mount Sinai.


Contacts and sources:
The Mount Sinai Health System


Publication:Increased advanced glycation end product and meat consumption is associated with childhood wheeze: analysis of the National Health and Nutrition Examination Survey.  Jing Gennie Wang, Bian Liu, Francesca Kroll, Corrine Hanson, Alfin Vicencio, Steven Coca, Jaime Uribarri, Sonali Bose. Thorax, Nov 2020 DOI: 10.1136/thoraxjnl-2020-216109